Rearrange code and cleanup

src/editor/selection.cc

@@ -0,0 +1,58 @@
+#include "editor/editor.h"
+
+char *get_selection(Editor *editor, uint32_t *out_len, Coord *out_start) {
+  std::shared_lock lock(editor->knot_mtx);
+  Coord start, end;
+  if (editor->cursor >= editor->selection) {
+    uint32_t prev_col, next_col;
+    switch (editor->selection_type) {
+    case CHAR:
+      start = editor->selection;
+      end = move_right(editor, editor->cursor, 1);
+      break;
+    case WORD:
+      word_boundaries(editor, editor->selection, &prev_col, &next_col, nullptr,
+                      nullptr);
+      start = {editor->selection.row, prev_col};
+      end = editor->cursor;
+      break;
+    case LINE:
+      start = {editor->selection.row, 0};
+      end = editor->cursor;
+      break;
+    }
+  } else {
+    start = editor->cursor;
+    uint32_t prev_col, next_col, line_len;
+    switch (editor->selection_type) {
+    case CHAR:
+      end = move_right(editor, editor->selection, 1);
+      break;
+    case WORD:
+      word_boundaries(editor, editor->selection, &prev_col, &next_col, nullptr,
+                      nullptr);
+      end = {editor->selection.row, next_col};
+      break;
+    case LINE:
+      LineIterator *it = begin_l_iter(editor->root, editor->selection.row);
+      char *line = next_line(it, &line_len);
+      if (!line)
+        return nullptr;
+      if (line_len > 0 && line[line_len - 1] == '\n')
+        line_len--;
+      end = {editor->selection.row, line_len};
+      free(it->buffer);
+      free(it);
+      break;
+    }
+  }
+  if (out_start)
+    *out_start = start;
+  uint32_t start_byte =
+      line_to_byte(editor->root, start.row, nullptr) + start.col;
+  uint32_t end_byte = line_to_byte(editor->root, end.row, nullptr) + end.col;
+  char *text = read(editor->root, start_byte, end_byte - start_byte);
+  if (out_len)
+    *out_len = end_byte - start_byte;
+  return text;
+}